铜（铅）—Ferron—氯化四苯胂络合物吸附波研究

在ＨＣｌ－六次甲基四胺介质中，铜（铅）－Ｆｅｒｒｏｎ－氯化四苯胂络合物产生灵敏的络合吸附波。峰电位分别为－０．４１Ｖ和－０．５７Ｖ。峰电流与铜、铜浓度分别在０．０００４－０．４μｇ／ｍＬ和０．００２－０．８μｇ／ｍＬ之间呈线性关系，检出限分别为０．０００２μｇ／ｍＬＣｕ和０．００１μｇ／ｍＬＰｂ。研究了极谱波的性质和电极反应机理。用拟定的方法连续测定水样和食品中的铜、铜，结果满意。     

铜（铅）－Ferron－氯化四苯胂络合物吸附波研究

在ＨＣｌ￣（－）六次甲基四胺介质（ｐＨ４．６２）中，铜（铅）－Ｆｅｒｒｏｎ氯化四苯胂络合物产生灵敏的络合吸附波。峰电位分别为－１．４１Ｖ和－０．５７Ｖ（Ｕｓ．ＳＣＥ）。峰电流与铜、铅浓度分别在０．０００４～０．４μｇ／ｍＬ和０．００２～０．８μｇ／ｍＬ之间呈线性关系，检出限分别为０．０００２μｇ／ｍＬＣｕ和０．００１μｇ／ｍＬＰｂ。研究了极谱波的性质和电极反应机理。用拟定的方法连续测定水样和食品中的铜、铅，结果满意。     

新—阶导数双峰光谱法解析及应用──测定NO_3~－和NO_2~－

本文通过对ＮＯ３－和ＮＯ２－的一阶导数光谱研究，提出利用它们各自导致光谱峰值的两种解析方法测定相互干扰的两组份含量，由于利用尽可能最大信息量和导数谱的特有功能，使测定ＮＯ３－和ＮＯ２－灵敏度分别为０．００５μｇ／ｍＬ、０．００９μｇ／ｍＬ（峰高－截矩比ｆ校正系数法）及０．００４μｇ／ｍｌ、０．００６μｇ／ｍＬ（双峰ｋ系组合导致法），线性范围皆为０～１．０μｇ／ｍＬ方法用于水样分析，结果令人满意。     

催化极谱测定痕量铬的研究

本文研究了含氨介质中铬（Ⅲ，Ⅵ）－α，α－联吡啶－亚硝酸钠体系的电化学行为。建立了测定痕量铬的方法。测定铬的范围为０．００４－０．０２８μｇ／ｍＬ和０．０４－０．２８μｇ／ｍＬ，检测下限为２．０×１０＾－＾３μｇ／ｍＬ，用以测定生物样品中痕量铬，变异系数为９．８％。     

焙烧富集分离—氢化物原子荧光法测定地质物料中痕量硒

本文研究了一种焙烧富集分离，氢化物－原子荧光法测定地质物料中痕量Ｓｅ方法。系统地了Ｓｅ富集分离条件，考查了３０多种元素在焙烧前后对测定Ｓｅ的影响。在选定的最佳实验条件下，方法检出下限为０．０１μｇ／ｇ和０．０８９μｇ／ｇ，线性范围０．００１－０．３μｇ／ｍＬ。样品中Ｓｅ含量水平为０．０３６μｇ／ｇ和０．０８９μｇ／ｇ时的测量精度（ＲＳＤ）分别为１０％和５．８％。加标回收率为９７－９９％。采用本方法     

钪－间氯偶氮安替比林络合物吸附波的研究

在ｐＨ４．３０的ＨＡｃ－ＮａＡｃ介质中，钪－间氯偶氮安替比林（ｍ－ＣＡＡ）－硫氰酸钾生成三元络合物，于－０．３５Ｖ（ｖｓ．ＳＣＥ）处出现一尖锐的极谱峰，峰电流与钪离子浓度在０．０２０～０．２０μｇ／ｍＬ范围内呈线性关系，检出限为０．０１０μｇ／ｍＬ．用多种电化学方法研究了极谱波的性质及电极反应机理．方法用于矿样中钪的测定，结果满意     

荧光分光光度法测定兽药中诺氟沙星

本文报道在ｐＨ２．６和β－环糊精存在下荧光分光光度法测定诺氟沙星，β－环糊精增强诺氟沙星荧光强度约２倍。其线性范围为７．８×１０－４μｇ／ｍＬ—１．５μｇ／ｍＬ，检测限为７．８×１０－４μｇ／ｍＬ，相对标准偏差为２．５％（ｎ＝５），方法用于兽药中诺氟沙星的测定，结果令人满意。     

18－冠－6修饰碳糊电极测定金的研究

本文研究了１８－冠－６修饰碳糊电极测定金的条件，金在０．５ｍｏｌ／ＬＨＣ１－０．００５ｍｏｌ／ＬＫＣ１底液中富集，介质交换到０．０１ｍｏｌ／ＬＨＣ１中进行测定。金（Ⅲ）浓度在０．１～１．０μｇ／ｍＬ范围内呈线性关系，相对标准偏差为９．７％，检出限为２０ｎｇ／ｍＬ。可不经预先分离直接测定矿样中的金，结果良好。并研究了Ａｕ（Ⅲ）在１８－冠－６碳糊修饰电极上的还原机理。     

还原菌修饰碳糊电极研究及对微量金的测定

研究用细菌修饰的碳糊电极对金离子的响应特性，并应用该电极检测水溶液中的金离子，金离子家度在１０－１００μｇ／ｍＬ。呈线性关系，重现性为３．４％，检测限达１ｎｇ／ｍＬ，电极具有制备简单，灵敏诬高等优点。文中还讨论了金离子在还原菌修饰的碳糊电极上的还原机理。     

脱乙酰壳多糖化学修饰电极测定铂的研究

用脱乙酰壳多糖修饰电极为工作电极，阳极溶出伏安法测定痕量铂。在ｐＨ＝２￣３的ＫＣｌ－ＨＣｌ底液中，－０．３Ｖ富集２ｍｉｎ，静止１５ｓ，以０．２Ｖ／ｓ扫速阳极溶出，峰电位在－０．１６Ｖ（ｖｓ．ＳＣＥ），铂（Ⅳ）离子浓度在０．５￣５．０μｇ／ｍＬ范围内与峰高呈线性关系。富集１０ｍｉｎ后，可检测０．０２５μｇ／ｍＬ铂（Ⅳ）。该法用于贵金属矿样的测定，无需分离，结果满意。用循环伏安法、紫外光谱和拉曼光谱研     

Anab initio SCF molecular orbital study of acetylcholine

A standard ab initio (STO 3 G) study indicates, in distinction to theab initio molecular fragment results, that the preferred conformation of acetylcholin is gauche.     

乙酰胆碱/胆碱电化学生物传感器研究进展

本文综述了近年来乙酰胆碱/胆碱电化学生物传感器的研究状况及其在分析化学中的应用进展。     

Disposable Stochastic Sensors for the Simultaneous Assay of Acetylcholine and Dopamine in Whole Blood Samples

Acetylcholine and dopamine are neurotransmitters important for aging and brain pathology. Their assay in whole blood is essential for fast and early detection of neurodegenerative disorders. Therefore, polymeric textile covered with a thin layer of Ag was used to provide stochastic sensors modified with maltodextrins presenting different dextrose equivalence: Maltodextrin I (dextrose equivalence 13.0–17.0), and Maltodextrin II (dextrose equivalence 16.5–19.5). These stochastic sensors were used reliable for both qualitative and quantitative analysis of acetylcholine and dopamine in whole blood samples. Their sensitivity and selectivity were high, and they were reliable for the assay of dopamine and acetylcholine in whole blood samples, with recoveries higher than 98.00%, and relative standard deviations (%) values lower than 1.00%.     

Application of a coated-wire electrode to an acetylcholine sensor

An acetylcholine sensor was constructed with acetylcholinesterase which was immobilized on a hydrogen ion-selective coated-wire electrode and fundamental properties of this sensor were investigated. Acetylcholine could be determined in the range 0.1–10 rum with response times of 3–10 min. The effects of pH and concentration of buffer solution on the determination and fluctuations in the data obtained with this sensor were also investigated. Possibilities for the practical use of this acetylcholine micro-sensor are suggested.     

A novel method developed for acetylcholine detection in royal jelly by using capillary electrophoresis coupled with electrogenerated chemiluminescence based on a simple reaction

A novel method for highly sensitive detection of acetylcholine in royal jelly was proposed by using CE coupled with electrogenerated chemiluminescence (ECL). Acetylcholine, which could not react with Tris(2,2′‐bipyridine)ruthenium(II) to strengthen its ECL signals, decomposed into trimethylamine and strengthened the ECL signals sharply when it was heated to its melting point. This reaction needed no additional reagent and it was mild, simple, stable and rapid, without any side reaction. By combining the above process with CE separation technique, trimethylamine in royal jelly was completely separated from interfering substances and was successfully detected within 4 min. The limit of detection for acetylcholine was found to be 6.3×10^?8 g/mL with a signal‐to‐noise ratio of 3:1. Acetylcholine in the royal jelly was detected to be 912±58 μg/g. The recoveries of acetylcholine chloride in the sample were in the ranges of 92–106%. The coefficients of variation for intra‐day and inter‐day reproducibility were equal to or less than 4.9 and 6.8%, respectively.     

Characterisation of a Platinum‐based Electrochemical Biosensor for Real‐time Neurochemical Analysis of Choline

A choline biosensor was characterised in detail to determine the effects of physiologically relevant parameters on the ability of the sensor to reliably detect neurochemical changes in choline. This first generation Pt‐based polymer enzyme composite sensor displayed excellent shelf‐life and biocompatibility with no significant decrease in choline sensitivity observed following 14 days of storage dry, or in ex‐vivo rodent brain tissue. However, subjecting the sensor to repeated calibrations and storage over the same period resulted in significant decreases (20–70 %) due to enzyme denaturation associated with the repeated calibration and storage cycles. Potential interference signals generated by the principal electroactive interferents present in the brain were minimal; typically <1 % of the choline current response at in vivo levels. Additionally, changing temperature over the physiologically relevant range of 34–40 °C had no effect on sensitivity, while increasing pH between 7.2 and 7.6 produced only a 5 % increase in signal. The limit of detection of the sensor was in the low μM range (0.11±0.02 μM), while the in vitro response time was determined to be less than the solution mixing time and within ca. 5 s, suggesting potential sub‐second in vivo response characteristics. Finally, the sensor was implanted in the striatum of freely moving rats and demonstrated reliable detection of physiological changes in choline in response to movement, and pharmacological manipulation by injection of choline chloride.     

Electrodeposited Nickel/Platinum Alloy as a Biosensor for Acetyl Choline

Nickel and platinum find extensive use in preparation of biosensors. In the present work, Ni/Pt alloy was plated on graphite to make acetylcholine sensor. The microstructure, surface composition and electrochemical performance of the electrode was analyzed by different techniques. The sensing performance was evaluated by cyclic voltammetry. The prepared alloy plate exhibited very good linear relationship between acetyl choline concentration and response current. The sensitivity and reproducibility of the prepared electrode were found better than other nickel electrodes reported.     

A highly sensitive and stable detection of acetylcholine by HPLC-osmium-horseradish peroxidase redox polymer electrode coated on a gold radial flow ring disk

To detect a low level of acetylcholine (Ach) output in the dialysate of rat frontal cortex, osmium-peroxidase redox polymer modified gold-ring disk electrode (Os-HRP-RDE) was fabricated in high-performance liquid chromatography (HPLC)-electrochemical detection (ECD). In comparison with platinum electrode, the sensitivity of acetylcholine detection by Os-HRP-RDE was stable during a day, the coefficient of variation was 0.95%, and the decrease of the sensitivity for 1 week was 5.4%. The Os-HRP-RDE could detect lower than 3 fmol of acetylcholine. The present technique, in the absence of acetylcholinesterase (AchE) inhibitor, is useful to facilitate physiological investigations of cholinergic neuronal activity in the brain.     

Sustained release of acetylcholine in rat hippocampus using a polyanhydride drug-delivery system

A biodegradable polymer drug-delivery system has been developed for the selective localized application of agents to brain parenchyma. The copolymer of poly[bis(p-carboxyphenoxy)propane] anhydride and sebacic acid (PCPP–SA) was impregnated with [³H]-acetylcholine (ACh) to form 1–5 μm microspheres. Drug-loaded microspheres were implanted into hippocampus bilaterally in 25 rats, and brain sections processed for autoradiography in groups of five animals at 2, 5, 10, 20 and 40 days, respectively. By densitometric analysis, the concentration of radiolabelled ACh in polymer and adjacent hippocampus rapidly decreased between 2 and 5 days, after which a gradual decrease in [³H]-ACh was observed up to 40 days. Between 2 and 40 days the concentration of radiolabelled ACh was reduced by 25.8% in polymer matrix and 40.1% in hippocampus. The spread of [³H]-label into adjacent brain parenchyma showed a similar temporal relationship, with initially wider dispersion at 2 days (44±3 μm), then a linear decrease in dispersion over the remaining period (10±0.9 μxm at 40 days), suggesting bulk flow of the radiolabel into hippocampus. Brain parenchyma showed only a minimal inflammatory reaction to the polyanhydride implants over all time periods. Polyanhydrides can provide localized continuous release of ACh to brain parenchyma, and may potentially be used to deliver various agents to brain in a number of clinical and experimental applications.     

Synthesis and Characterization of Enantiomerically Pure cis‐ and trans‐3‐Fluoro‐2,4‐dioxa‐7‐aza‐3‐phosphadecalin 3‐Oxides as Acetylcholine Mimetics and Inhibitors of Acetylcholinesterase

The title compounds, the P(3)‐axially and P(3)‐equatorially substituted cis‐ and trans‐configured 7‐benzyl‐3‐fluoro‐2,4‐dioxa‐7‐aza‐3‐phosphadecalin 3‐oxides (=7‐benzyl‐3‐fluoro‐2,4‐dioxa‐7‐aza‐3‐phosphabicyclo[4.4.0]decane 3‐oxides=5‐benzyl‐2‐fluorohexahydro‐4H‐1,3,2‐dioxaphosphorino[5,4‐b]pyridine 2‐oxides) were prepared (ee>99%) and fully characterized (Schemes 2 and 4). The absolute configurations were established from that of their precursors, the enantiomerically pure cis‐ and trans‐1‐benzyl‐3‐hydroxypiperidine‐2‐methanols which were unambiguously assigned. Being configuratively fixed and conformationally constrained phosphorus analogues of acetylcholine, they mimic rotamers of acetylcholine and are suitable probes for the investigation of molecular interactions with acetylcholinesterase. As determined by kinetic methods, the compounds are irreversible inhibitors of the enzyme displaying significant stereoselectivity.